"On the path below Salisbury Crags in a disused quarry, stands an isolated outcrop known as ‘Hutton’s Rock’. The rock illustrates a vein of iron ore (haematite) several centimetres thick, that runs through the teschenite rock of the Salisbury Crags sill intrusion. The vein formed as super-heated solutions rich in iron, percolated through fissures in the cooling rock mass.

The rock is of considerable historical significance, as James Hutton is reputed to have requested that this unusual and interesting geological feature, be saved from quarrying. The site is the earliest known example of geological conservation in the world."

(Scottish Geology Trust)

this is not it, but I'm fascinated by the history of the area